At the request of the French Ministry of Foreign Affairs, the Institute for Research into Development (IRD) brought together a panel experts to investigate what is really happening as regards the growing tendency of bright people to move from South to North (usually first in order to study) and then to form networks. How do these diasporas organize themselves? Does this offset the loss of skills triggered by their departure from their countries of origin and does it make sense to encourage the formation of these networks, for example through appropriate public policies? The responses to these varied questions, as well as others, are presented in a report entitled Diasporas scientifiques (Paris: IRD Éditions, 2003). Rémi Barré, one of the contributors, presents the main conclusions.